Risk Factors and Prevention

A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health care choices.

The following factors can raise a person’s risk of developing HCC. The main risks in the United States are chronic liver infection with the hepatitis B or hepatitis C virus or cirrhosis of the liver. HCC usually develops several decades after such an infection starts.

Viral hepatitis. Viral hepatitis is the largest risk factor for this type of cancer. Hepatitis viruses are viruses that infect the liver. Two common types are hepatitis B and hepatitis C. People who are carriers of the hepatitis B virus face up to a 100-fold increased risk of developing adult primary liver cancer.

Viral hepatitis can be transmitted through exposure to another person's blood or bodily fluids through injury, by sharing needles during drug use, or by sexual contact. In the case of hepatitis B, an unborn baby or infant can become infected from an infected mother, although this can be avoided by vaccinating the baby. If you develop acute hepatitis B or C and then “clear the virus,” you have no increased risk of liver cancer. Only people who don’t clear the virus (those who become “carriers”) are at an increased risk. Your doctor will be able to perform blood tests that tell if you have cleared the virus.

Cirrhosis. Cirrhosis develops when liver cells are damaged and are replaced by scar tissue. Most cirrhosis in the United States is caused by alcohol abuse. Other causes are viral hepatitis (types B and C, as mentioned above), too much iron in the liver from a disease called hemochromatosis, and some other rare types of chronic liver disease.

Age. In the United States, adult primary liver cancer occurs most often in people over age 60.

Gender. Men are more likely than women to develop this type of cancer.

Environmental factors. Some environmental factors may increase the risk of liver cancer, such as exposure to certain chemicals or eating foods contaminated with the mold aflatoxin.

Risk factors are cumulative, meaning that having more than one risk factor increases the risk even more. For instance, a person who carries both hepatitis B and C has a higher risk than a person carrying one type of the virus.

Prevention

Most cases of HCC in the United States can be avoided by preventing viral hepatitis and cirrhosis. A vaccine can protect healthy people from contracting hepatitis B. In fact, the U.S. Centers for Disease Control and Prevention recommends that all children should have this vaccination. There is no vaccine against hepatitis C, which is most often associated with current or previous intravenous (IV) drug abuse. Blood banks in the United States check donated blood to make certain that blood carrying the hepatitis viruses is not used.

Cirrhosis can be avoided by not abusing alcohol and preventing viral hepatitis. Most industrialized countries have regulations to protect people from cancer-causing chemicals; in the United States, such regulations have virtually eliminated these chemicals as a cause of adult primary liver cancer.

There is increasing evidence that certain medications can control chronic hepatitis B or C infection, and thereby reduce the inflammation they cause in the liver. This may reduce the risk of cancer development, particularly if the medications are taken before cirrhosis develops. It is recommended that information about such treatment come from a hepatologist, which is a doctor who specializes in diseases of the liver.

If you know you have cirrhosis or other risk factors, it is important to discuss with your doctor whether you should be regularly screened for liver cancer. Early detection, before any symptoms have developed, may increase the likelihood of successful treatment. Hepatologists are the doctors with the most experience in screening for primary liver cancer. You may also see the term “surveillance” used to explain this, but, in effect, this means the same as screening.